Changes

*In 1950 it absorbed three teams from the All-America Football Conference (the [[Cleveland Browns]], the [[San Francisco 49ers]], and a team called the Baltimore Colts which is not related to the current franchise called the [[Indianapolis Colts]]).

*In 1950 it absorbed three teams from the All-America Football Conference (the [[Cleveland Browns]], the [[San Francisco 49ers]], and a team called the Baltimore Colts which is not related to the current franchise called the [[Indianapolis Colts]]).

*In 1970 it merged with the American Football League, which began operations in 1960.  As part of the merger agreement, beginning in 1967 it hosted a championship game between the leagues, which is now today's [[Super Bowl]].  Also, in order to equalize the number of teams between what would be the [[National Football Conference]] (comprised of NFL teams) and the [[American Football Conference]] (comprised of AFL teams), three NFL teams -- the Browns, the Colts and the [[Pittsburgh Steelers]] -- were moved to the AFC.

*In 1970 it merged with the American Football League, which began operations in 1960.  As part of the merger agreement, beginning in 1967 it hosted a championship game between the leagues, which is now today's [[Super Bowl]].  Also, in order to equalize the number of teams between what would be the [[National Football Conference]] (comprised of NFL teams) and the [[American Football Conference]] (comprised of AFL teams), three NFL teams -- the Browns, the Colts and the [[Pittsburgh Steelers]] -- were moved to the AFC.

Otherwise, the league has grown through expansions into new markets, which has proven tremendously successful: as an example it expanded into [[Dallas]] in 1960 with the [[Dallas Cowboys]] franchise, which is the league's most valuable and among the most valuable of all sports franchises worldwide.  It is also very active in teams relocating to other markets (and sometimes returning, such as the Los Angeles Rams moving to St. Louis and then returning to Los Angeles).

Otherwise, the league has grown through expansions into new markets, which has proven tremendously successful: as an example it expanded into [[Dallas]] in 1960 with the [[Dallas Cowboys]] franchise, which is the league's most valuable and among the most valuable of all sports franchises worldwide.  It is also very active in teams relocating to other markets (and sometimes returning, such as the Los Angeles Rams moving from Cleveland to Los Angeles, then moving to St. Louis and then returning back to Los Angeles).

The league would begin to supplant baseball as America's most popular spectator sport in 1958, when the then-NFL Championship Game between the Colts and the [[New York Giants]] was broadcast nationwide (though ironically not in New York City) and ended in a sudden-death overtime win by the Colts.

The league would begin to supplant baseball as America's most popular spectator sport in 1958, when the then-NFL Championship Game between the Colts and the [[New York Giants]] was broadcast nationwide (though ironically not in New York City) and ended in a sudden-death overtime win by the Colts.